chore(reactivity): fix typo in types (#4889)

packages/reactivity/src/computed.ts

@@ -4,11 +4,11 @@ import { isFunction, NOOP } from '@vue/shared'
 import { ReactiveFlags, toRaw } from './reactive'
 import { Dep } from './dep'
 
-declare const ComoutedRefSymbol: unique symbol
+declare const ComputedRefSymbol: unique symbol
 
 export interface ComputedRef<T = any> extends WritableComputedRef<T> {
   readonly value: T
-  [ComoutedRefSymbol]: true
+  [ComputedRefSymbol]: true
 }
 
 export interface WritableComputedRef<T> extends Ref<T> {